Almost two years ago now I purchased a new 66cc manual clutch Chinese engine. At the time I was told it was an 80cc engine, but I now understand there is no such thing as an 80cc Chinese bicycle engine and that they are in fact only 66cc in capacity. I made a number of attempts to fit this engine to a variety of English made bicycles, only none of the bicycles were really ideal for my purpose. You see I wear long skirts for religious reasons and none of the classic English ladies frames I was trying to build a motorised bicycle around had space for both an engine and a long skirted rider.
Then a picture of a Mixte frame conversion came to light and at once I saw that this was what I was looking for.
From what I could see this conversion was everything I could want. The frame was a modern Mixte, but the wheels, mudguards, forks & etc were all classic 3 speed English bicycle parts. As you can see it's a tight fit to get a Chinese engine into a Mixte frame and it involves quite a bit of lifting and rotating the engine as well as holding one's mouth right to get it into place to can tell you.
The red Mixte frame in the picture has a wider spacing between the twin frame tubes where they cross the seat tube than the frames commonly available here in New Zealand. Because of this I found it almost impossible to get the carb to fit between the twin frame tubes. Perhaps I could have made a custom intake manifold, only I didn't want to do this. I wanted my carb to fit between the tubes using the standard intake manifold.
The blue frame isn't the actual frame I'm using, - the picture is intended to show you what I'm having to do in order to get the carb if fit. After cutting through the crosstube between the twin tubes I was then able to spread the tubes sufficiently to allow the carb to fit between them. Once I know exactly how far to spread the tubes to obtain a good working fit, a new longer crosstube will be made up and welded in place.
To complete the conversion and make it a proper rolling bicycle I have a set of Rudge forks, chainwheel, chainguard and 26 inch wheels with 'Westrick' rims, BSA coaster hub as well as Raleigh pattern mudguards and a classic brand new 'Middlemore' sprung bicycle seat. I'm sure I can find a nice period Miller lighting set to finish it off nicely as well.
If it can be neatly done I will fit a Rudge head badge to the Mixte headstock which should set the purists a-scratching their heads.
Colour? Black with white mudguards, - what else?
Black mudguards might be more classic, but white mudguards are more visible in traffic. If I get really keen I might even attempt a little pinstriping in red and gold on the frame.